Heretofore high energy feed supplements have been used extensively for cattle, hogs, sheep and the like, such supplements conventionally being in particulate or liquid forms and comprising fat, urea, vitamins minerals, pharmaceuticals and the like. More recently, such supplements have been available mixed with molasses and formed into a hard, dense, non-porous, vitreous mass, sometimes termed, or mistermed, a "block". In the latter regard, the term "block" is presently thought to be inappropriate because it implies a solid, and such "blocks[ do not exhibit all the characteristics of conventional solids. Although it is true that a properly formed block of such feed supplement will shatter like glass when struck, such blocks exhibit other characteristics that are not like conventional solids. For example, if a solid object of any substantial weight is placed on the top of even a properly formed non-porous vitreous block, in a relatively short period of time, the object will sink completely into, and be encased by, the block without any apparent softening of the block. In this light, and in light of other similar examples indicating block material flowage, such blocks might more appropriately be called extremely viscous fluids, or alternately called hydroscopic gels transiently in a crystaline form. Nevertheless, for consistency with the prior art and economy of description, the term "block" will sometimes be used herein.
Hard, dense, non-porous vitreous molasses-based animal feed supplement blocks have met with substantial commercial acceptance because such blocks are convenient to handle as compared to particulate or liquid forms of feed supplement. Additionally and importantly, these blocks are especially convenient to feed by virtue of the hygroscopic characteristic of molasses blocks whereby only the surface of a properly formed block is softened from a glass-like state to an edible condition upon continued exposure to moist air. Because of this characteristic, the contents of such blocks become only incrementally available as feed, at a predictable rate, thereby inhibiting over feeding.
A method of making such molasses-based animal feed supplement vitreous blocks is disclosed in the U.S. Pat. No. 3,961,081 to McKenzie wherein it is presented that to form dense molasses blocks, the water content of the molasses has to be reduced to less than 5%. The McKenzie method basically comprises a preliminary step of heating a composition of molasses mixed with other animal feed supplements to a temperature within the range of 225.degree. F. to 300.degree. F. to partially reduce the water content of the molasses so that the remainder thereof is 5% or greater. Since molasses of the type utilized by McKenzie is normally comprised of about 20% to 25% water content, such water content reduction amounts to removal of not more than 75% to 80% of the molasses water content. Of particular significance is the fact that McKenzie discloses the requirement that after heating, the composition is then subjected to a substantial vacuum to further substantially reduce the remaining water content of the molasses to about 3% prior to forming the composition into blocks. After formation the blocks are allowed to cool and cure at ambient conditions until hardened into a dense vitreous form. While this McKenzie patent method has met with some success in forming vitreous molasses blocks, it is important that during the heating stage of this method, care must be taken to avoid development of hot spots in the composition, as well as to avoid any substantial expansion and foaming. Such hot spots are considered undesirable because they may damage or burn the molasses or other more heat-sensitive additives thereby lowering the quality of the resultant product. Substantial expansion, which may occur to the extent of as much as 600%, and foaming are considered undesirable because such interferes with the physical handling of the molasses during processing, reduces production, and, unless controlled, also reduces the density of the resulting blocks. Reduced block density results in premature and internal block softening. Additionally, the McKenzie method requires machinery for the practice thereof, particularly the application of vacuum to the composition to dehydrate the same, that is relatively complicated, extensive and energy intensive and production from such machinery is not as great as might be desired.